Nanocrystalline indium-tin alloy particles, having the composition of In95Sn5, were prepared by the inert-gas condensation technique and then examined for the possible formation of a core-shell structure after oxidation and different heat treatments. The crystalline structure and phase(s) of the as-prepared and heat-treated samples were investigated by x-ray diffraction, differential scanning calorimetry, small-angle x-ray scattering, and high-resolution electron microscopy. The results showed that the oxidation treatment led to highly faceted indium-tin oxide nanoparticles and indium-tin alloy grains with sizes in the nanometer range. No particles having a core-shell structure consisting of InSn alloy coated with oxide were detected. (C) 2008 American Vacuum Society.